The present invention relates to an intelligent current distribution system, comprising
a current distribution cable for supplying current to loads;
a message communication bus for controlling the current supply;
a plurality of predefined control messages for performing a plurality of predefined functions, each control message including specified data for performing a predefined function;
intelligent contact sockets connected to the current distribution cable and message communication bus:
output connectors included in a plurality or all of the sockets for supplying current to the loads;
input connectors included in a plurality or all of the sockets for inputting said control messages into the system;
switches included in a plurality or all of the sockets for distributing current to the output connectors in a controlled manner;
control electronics included in each socket for controlling the message communication and, when necessary, for controlling the switches on the basis of the control messages received from the communication bus or from the socket input connector.
The invention relates also to a method for manufacturing an intelligent current distribution system, especially for vehicles, in which method a current distribution cable is fitted with intelligent connecting sockets provided with output pins for supplying current to loads connected to the system and with switches for distributing current to the output pins as well as with control electronics for controlling the switches on the basis of control commands received from a message communication bus of the cable or from a socket input connector.
This type of current distribution system is prior known e.g. from publication WO 93/10591, WO 95/15594, EP-564943, AND WO 97/02965.
A weakness in these prior known systems is that too much intelligence required for commanding and control of functions is concentrated in the central control unit of the system, whereby the communication becomes congested and the system is impaired in terms of its operating reliability. In order to reduce this drawback there has been proposed in European patent application EP-0 791 506 A2 to use highly intelligent node controllers under control of a central controller which sends a single command addressed to the proper intelligent node which in turn is provided with individual operation instructions for controlling the load connected to the node. One of the node controllers may be employed as a central controller. Because of need of the central controller there is still considerable reciprocating traffic between every node and the central controller which has to transmit every single command, query its performance and receive any condition messages from the nodes. Addressing the commands with node specific addresses provides an additional burden to data transmission because most of the commands or control messages are planned to be recognized or identified by several nodes.
On the other hand, the decentralization of intelligence in such a manner that the connector sockets would be provided with individual intelligence, as required by the different operating needs of various loads and actuators connected therewith, creates production-related problems for manufacturing various optional system configurations on an automated line.
An object of the invention is to provide an intelligent current distribution system, wherein not only the intelligence required for the individually instructed control of the functions of sockets has been removed from the central control unit of the system but also the need of a predestinated central control unit and socket specifically addressed commands therefrom are avoided and instead, the mastering control as well as transmission and identification of function specifically addressed commands are decentralized to the sockets, whereby the required communication further diminishes and the commands or control messages become simpler.
Another object of the invention; is to provide a method, whereby a current distribution system can be manufactured by automated production despite the fact that the intelligence required for the individual control of the functions of sockets has been removed from the central unit of the system and decentralized to the sockets.
A further object of the invention is to provide flexible automated production, capable of manufacturing a cable set for a single system one at a time, while keeping in mind the above-mentioned object for decentralizing the intelligence to sockets.
These objects of the invention are achieved on the basis of the characterizing features set forth in claim 1 for the system and on the basis of the characterizing features set forth in claim 10 for the method.
The non-independent claims disclose preferred embodiments of the invention.